That's not surprising, said WLWT News 5 investigative reporter Todd Dykes, since at any given time, on any given day dangerous chemicals roll through Cincinnati by train.

What people might not realize is how little knowledge local experts have about what exactly is riding the rails.

"We collect inventories from facilities who store hazardous materials that are required to be reported to the county," Rick Jones, coordinator of Hamilton County's Local Emergency Planning Committee, said. "And we put that out to the emergency responders and other jurisdictions. Transportation has some exemptions, of course, so they don't actually have to report what's coming in and out of their yard on a daily basis."

Jones recently conducted a training exercise with first responders and chemical experts, role playing a train crash involving the same chemical which is causing so much chaos near Knoxville, Tennessee."We spent a lot of time planning on an incident just like that here in Cincinnati earlier this year," Jones said. "An acrylonitrile car coming across the rails, derails, leaks or catches fire."

Jones described acrylonitrile, a flammable liquid used in industrial processes including the manufacture of plastics, this way: "Very toxic, very flammable, and just as important is its decomposition products. When it's heated or involved in a fire it can put off a hydrogen cyanide-type of material, which is your central nervous system-type impact. And that requires some additional specialized medical treatment. So it can be quite complicated."

While rail companies are not required to report exactly what's in their train cars, Jones said CSX and other companies with yards near downtown Cincinnati, like Norfolk Southern, are good training partners.

"Their best advice to us is if you have to … plan,” Jones said. “It would be logical to assume that if you can think of just about any hazardous material it could be coming through our (Queensgate or other local) yard on a daily basis. We think that's good advice (and) we pretty much plan for some of the worst factors that could come through, one being acrylonitrile."

Train shipments are governed by federal guidelines, and as a result trains carrying hazardous materials have to be properly marked with placards denoting what's inside, and specialists are required to be on standby to answer questions in case an accident happens.

Those and other requirements are designed to help emergency workers respond more rapidly to dangerous situations and begin evacuations as quickly as possible.

With the pervasiveness of technology, many people wonder if some kind of connected device could help public service agencies gain more insight into the contents of rail cars.

"You know, there's still some issues we have to work out," Jones said. "The community has a right know, and that's one of the things that really drives my office is the community's right to know about hazardous materials in the community. But the modes of transportation here, especially with I-75, I-71, the Ohio River, and thousands and thousands of different containers coming through on a daily basis. How practically to learn about those things other than what's already out there, as far as a placard or something you can (reference during) an emergency quickly, I think that's a little ways off."